Thank you for the suggestion. I will investigate it a little more. It looks promising for a way to provide the information I need in XP and Server 2003. I did not specify the OS's I need a solution for though (definite oversight on my part). I am looking for a technique that will with Windows 2000 and forward, so I am still looking for other techniques as well that work in win2k.

Thanks again for the WMI link. I will almost certainly incorporate it into my detection technique (I already have 4 techniques used to detect IDE hard drive serial numbers. The redundancy is very welcome when the different techniques can fail for reasons I do not completely understand).

And to complicate things a little further, there is also one other issue to contend with. I have found a technique that does work with SCSI hard drives as far as I can tell (referenced it against a tool that uses the WMI technique Bob suggested above and got the same results). However, it does not work when a SCSI raid controller is present. It instead returns an erroneous value that people have suggested is a Raid Controller Serial Number that is not unique. If anyone knows of a way to deal with Raid Controllers and SCSI drives, I would appreciate any info.